The Effect of Dilapan-S Compared to Foley Catheter for Pre-Induction Cervical Ripening in Primigravid Pregnancy: A Randomized Clinical Trial

Background & Objective: Induction of labor is a common obstetric procedure that relies heavily on cervical ripening. The methods for achieving cervical ripening include mechanical interventions and pharmacological agents. This study was conducted with aim to compare the efficacy of the synthetic osmotic cervical dilator named Dilapan-S with the Foley Catheter (FC) in cervical ripening. Materials & Methods: This open-label randomized clinical trial was conducted on 160 pregnant women with a Bishop score ≤4 indicated for Normal Vaginal Delivery (NVD). The subjects were randomly assigned to the FC or Dilapan-S group. Then, the study outcomes were compared between the two study groups. Data were analyzed using SPSS software (version 20). P<0.05 was considered significant. Results: There was no significant difference between the two study groups regarding baseline information. Bishop score increased significantly (P<0.001) in both groups. The mean active phase duration was 5.63±2.36 hours in the FC group and 6.85±2.51 hours in the Dilapan group, which was significantly higher in the Dilapan group (P=0.002). The frequency of oxytocin administration was 69 cases (86.3%) in the FC group compared to 78 cases (97.5%) in the Dilapan-S group (P=0.009). The average 1-minute Apgar score was 8.04±0.81 points in the FC group and 8.36±0.64 points in the Dilapan group, which was significantly higher in the Dilapan group (P=0.006). NICU admissions were reported in 18 (22.5%) neonates in the FC group and 14(17.5%) in the Dilapan-S group (P=0.017). Conclusion: Dilapan-S is an effective and safe method for pre-induction cervical ripening, demonstrating favorable changes in Bishop score without significant adverse maternal or neonatal effects.